The present invention provides an improvement for the recovery of lovastatin, compactin or pravastatin from fermentation broths.
Lovastatin for instance is produced as a secondary metabolite by various microorganisms such as Aspergillus terreus (U.S. Pat. No. 4,231,938) or Monascus ruber (U.S. Pat. No. 4,323,648). During the fermentation also lovastatin related byproducts such as 4-acetyl lovastatin are produced.
Lovastatin, usually in the acid form, can be isolated from the fermentation broth in different ways. The first stage is formed by purification yielding crude crystals. These crude crystals still comprise related compounds like 4-acetyl lovastatin. As lovastatin is a pharmaceutical compound that has to meet high purity requirements, additional purification in order to remove the lovastatin related impurities is necessary. The lovastatin-related impurities are generally removed by multiple recrystallizations, by column chromatography as described in U.S. Pat. No. 4,231,938 or preparative HPLC (WO 92/16276), decreasing the yield significantly.